The reason that jesus submitted to the baptism of John was not because he was converting to christianity but to set an example for the people of Irael . John did not baptize in the name of the father son and holy spirit but was only a show of repentance for the nation so all the people that John baptized the apostles had to rebaptize after jesus died and ascended to heaven . jesus was born anointed with holy spirit he did not have to appeal to God for a clean conscience even tho the spirit came in the form of a dove and God also made clear that jesus was the holy one of Irael before the apostles . IMO
I think people should be batized as adults as we know that kids are just too immature to set an example .